Manitoba's fight with the dreaded zebra mussel on Lake Winnipeg will be a long-term war the province hopes won't break out on numerous other fronts.
On Monday, Conservation and Water Stewardship Minister Gord Mackintosh announced tests have revealed more evidence the freshwater mollusk has invaded the world's 11th-largest freshwater lake.
The revelation comes less than two months after what the government described as a successful effort to rid four Lake Winnipeg harbours of the pest, which can spur blue-green algae growth, harm fish and clog water pipes.
What are zebra mussels and how are they spread?
Zebra mussels are a freshwater mollusk about the size of a fingernail that attach to solid surfaces in water. Adults are up to 3.8 centimetres long and have D-shaped shells with alternating yellow and brownish- coloured stripes. They are spread mainly from the transportation of boats from one water body to another.
Why should we care?
If the pests thrive, they can foul beaches, curb production of certain fish, contribute to the growth of green-algae blooms on the lake and clog water-treatment plant intake pipes and effluent-discharge pipes.
What is being done about the problem in Manitoba?
The province is beefing up an advertising campaign to warn boaters and Manitobans in general about the problem. It is monitoring Lake Winnipeg for more signs of the problem and is starting to test other lakes with high volumes of boaters. The government will also introduce legislation, as early as this fall, to strengthen its hand in battling the mollusc.
-- Sources: Province of Manitoba, Minnesota Department of Natural Resources, Free Press files
"Today, it just confirms, I think, everybody's suspicion since last fall that we could have zebra mussels lurking in Lake Winnipeg outside of the harbours as well," Mackintosh said.
Lake monitoring turned up nine larval zebra mussels in three samples taken from the southeast and eastern portion of the south basin, including east of where the Red River enters the lake, offshore from Grand Marais and in Traverse Bay.
More than 60 samples were analyzed from the south basin, the narrows and the lake's north basin. They were collected by provincial staff and researchers aboard the Lake Winnipeg research ship MV Namao. More tests will be conducted through the open-water season.
Mackintosh said Manitoba is drafting legislation, patterned on a Minnesota law, to strengthen its ability to deal with the problem. The legislation would introduce new rules regarding the handling and transportation of boats. A bill is expected to be introduced in the legislature as early as this fall.
He also announced a new awareness campaign, entitled Don't Move a Mussel! to encourage boaters to be vigilant in checking their watercraft for zebra mussels. (The tag line is also used in other jurisdictions.)
"Government has a role in reducing the risk (of infestation) but only individual action can prevent infestation from boats with certainty," he said.
Now that Lake Winnipeg has the zebra mussel, the best the province can do is to contain and manage it as best it can, Mackintosh said. The other main effort will be to prevent it from infesting other lakes.
And with tens of thousands of boaters travelling through the province each year, accessing rivers and lakes at private as well as public locations, it's a daunting task, the minister said. "It takes just one boat to infest an entire lake or waterway. That is a huge challenge to manage, but we can't just give up."
Laureen Janusz, a provincial fish biologist, said boaters can help contain the problem in Lake Winnipeg by taking precautions.
"While we're looking at Lake Winnipeg as an infested water body, your ability to control that spread or minimize that spread will be by cleaning your boats... " Janusz said Monday. "Any efforts that individuals can do to... clean their boats before they move from one launch area to another within Lake Winnipeg is really key right now," she said.
The potash treatments carried out in May and June at harbours at Winnipeg Beach, Gimli, Arnes and Balsam Bay were "very successful" in slowing the spread of the infestation, Janusz said.
To prevent the spread of zebra mussels from Lake Winnipeg to other water bodies, boaters are asked to ensure they clean, drain and dry their equipment and dispose of any bait and water every time they leave the lake, before entering another harbour on the lake or haul their boat to another water body.
Manitoba has spent $1 million over the last several years on zebra-mussel prevention, Mackintosh said. It has beefed up inspections of boats coming from out of province and, with the help of Manitoba Hydro, now has acquired and deployed five portable decontamination units to purge aquatic invasive species from the undersides of boats. The units are operating at Gimli Harbour, Winnipeg Beach, Selkirk Park among other locations.
Conservative conservation and water stewardship critic Shannon Martin said the province waited too long to announce the beginnings of a long-term strategy to deal with the problem.
The government could have announced a broader approach to tackling the issue last fall when it confirmed evidence of zebra mussels had been found in the lake, he said. Instead, it was content to grab headlines with its harbour-treatment plan, which, while important, was not going to make the creatures disappear, he said.
"We've had jurisdictions south of the border who have been fighting this infestation for some time," Martin said, arguing Manitoba could have more quickly followed their lead.